Experimental research in social cognition demonstrates the psychological processes at the basis of the relational self. It suggests that the self is relational or bound up with those whom one has known and loved, whether living or deceased. The self varies as a function of these prior relationships, which have an impact on current ones. The potentialities, pains, and pleasures brought to new situations with new people are often defined (and at times constrained) by the particular significant-other representation called to mind. This research, conducted with federal support (an R01 from NIMH), constitutes the first experimental demonstration of the century-old clinical concept transference in everyday interpersonal relations (e.g., Andersen & Glassman, 1996). Previous relationships supply the person with an underlying substrate or repertoire of relational selves. The project's objective is the preparation of an academic book, a scholarly, scientific review that is comprehensive, critical, and analytic, to locate this research in broader literatures on the self, emotion, and self-regulation, identifying consistent themes and gaps in the literature, questions in need of examination, and mental health implications. Longstanding interest in the clinical assumption that human suffering may result from re-experiencing old relationship patterns in new interpersonal contexts highlights the mental health relevance of this work. A book on the relational self is needed both because too few researchers in psychology and psychiatry have kept abreast of these empirical findings in psychological science and because health care professionals and policymakers are also likely to find them of value. This scholarly book on the relational self will be the first to address the social-cognitive process of transference. It will integrate experimental research with longstanding personality and clinical theory to highlight the implications for mental health and clinical practice in ways that are accessible both to researchers and to practitioners. It will also offer a window onto variability and stability in the self through underlying processes of cognitive activation and use, which do not rely on conscious awareness or attention. Because the guiding framework is an if-then model of personality (e.g., Mischel & Shoda, 1995) that focuses on meaningful contextual variability in the self, this work on the relational self is also theoretically integrative and thus of value in this way.